Flavor enhancing methods

ABSTRACT

α-keto acids and certain precursors and derivatives thereof, particularly those selected from the group which consists of glyoxylic acid, 2-oxo-propanoic acid, 2-oxo-butanoic acid, 3-methyl-2-oxo butanoic acid, 3-methyl-2-oxo pentanoic acid, 4-methyl-2-oxo pentanoic acid, 3-hydroxy-2-oxo-propanoic acid, oxalacetic acid, 2-oxo-glutaric acid, 2-oxo-3-phenyl-propanoic acid, 3-(4-hydroxy-phenyl)-2-oxo-propanoic acid, 2-oxo-1H-indole-3-propanoic acid, 2-oxo-1H-imidazole-4-propanoic acid, 4-methylthio-2-oxo-butanoic acid, 3-mercapto-2-oxo-propanoic acid, 3-hydroxy-2-oxo-butanoic acid, 6-amino-2-oxo-hexanoic acid and 5-guanido-2-oxo-pentanoic acid, and precursors and derivatives thereof that are capable of being formed from or releasing said acids in the use medium, are useful as flavouring ingredients. Such ingredients are useful for preparing flavouring compositions and a wide variety of flavoured foodstuffs to which they impart greater creaminess and bulkiness so that they have heightened effect in the mouth and generally an enhanced mouthfeel. They are also useful for enhancing the sweetness of foods sweetened with natural or artificial sweeteners, and giving it a more natural character.

TECHNICAL FIELD

The present invention relates to the flavoring industry and moreparticularly to the use of α-keto-acids as flavoring ingredients for thepreparation of flavoring compositions and/or flavored food orpharmaceutical products.

Tha α-keto-acids are a group of compounds which obey the general formula

wherein symbol R can represent hydrogen or a large variety of alkylradicals, saturated or unsaturated, linear or branched, optionallysubstituted by hydroxy, amino, phenyl, hydroxy-phenyl, carboxy,mercapto, methylthio, guanidino and other groups. More than a hundred ofsuch compounds are presently known and the invention concerns moreparticularly the use as a flavoring ingredient of a certain number ofthese acids mentioned below, which are edible.

PRIOR ART

A good number of these compounds are known as components of naturalproducts, wherein they are formed by fermentation of amino acidsresulting from the enzymatic transformation of proteins. Thus, severalof these acids have been found, among others, in cocoa, in several typesof cheese, or yet in beer.

It is also known that the α-keto-acids can play a decisive role in themetabolism of living beings when acting as precursors of essential andsemi-essential amino acids, and this renders them useful in thepharmaceutical industry. In this context, they have been known to beused, for example, as active principles in medications intended for thetreatment of kidney or liver diseases. However, their use to this effectpresents some difficulties related to their unpleasant odor and taste(see for example, FR 2 419 723 and EP 406 811), and this has prompted anumber of researchers to propose particular carrier systems, e.g.cyclodextrine clathrates (EP 406 811), which make it possible topalliate such problems.

In view of the preceding comments, it may not be surprising to observethat, in spite of the many prior art reports related to the naturaloccurrence of certain of these keto-acids and to their use fortherapeutical applications, to our knowledge, it has never beensuggested to apply them as active flavoring ingredients, to improve thetaste and aroma of edible products, by adding them to these products inessentially pure form, i.e. devoid of the natural substances which mayaccompany them in a natural product.

We have now surprisingly discovered that the above-mentioned compoundsare very advantageous flavoring ingredients, and that the scope of theiruse to this effect can be extremely general. We have thus establishedthat, upon addition of one or several of these compounds to flavoringcompositions o r concentrated flavors of a large variety, one couldimprove in an unexpected manner the taste of said compositions andconcentrates, namely the “mouthfeel” of these products, withoutobserving any harmful organoleptic effect, unlike what could have beenexpected in view of the prior art.

DESCRIPTION OF THE INVENTION

Thus, an object of the present invention is an artificial flavoringcomposition containing as an active ingredient one or several compoundsselected from the group consisting of the α-keto-acids in essentiallypure form, as well as their edible derivatives and precursorssusceptible of being formed from said acids, respectively liberate saidacids, in the utilization medium.

By an α-keto-acid in essentially pure form it is understood here anα-keto-acid which is not accompanied by the substances with which it mayoccur in a natural origin product, nor in the same proportions.

According to a preferred embodiment of the flavoring composition of theinvention, the active ingredient is formed of one or several compoundsselected in the group consisting of glyoxylic, 2-oxo-propanoic,2-oxo-butanoic, 3-methyl-2-oxo-butanoic, 3-methyl-2-oxo-pentanoic,4-methyl-2-oxo-pentanoic, 3-hydroxy-2-oxo-propanoic, oxalacetic,2-oxo-glutaric, 2-oxo-3-phenyl-propanoic,3-(4-hydroxyphenyl)-2-oxo-propanoic, 2-oxo-1H-indole-3-propanoic,2-oxo-1H-imidazole-4-propanoic, 4-methylthio-2-oxo-butanoic,3-mercapto-2-oxo-propanoic, 3-hydroxy-2-oxo-butanoic,6-amino-2-oxo-hexanoic and 5-guanidino-2-oxo-pentanoic acids, and by theedible derivatives and precursors of these acids susceptible of being orof liberating the latter in the utilization medium.

By “utilization medium” it is meant here, either the medium of theactual flavoring composition, which will also typically contain one ormore current flavoring ingredients of natural or synthetic origin,optionally in admixture with the usual solvents and adjuvants, or themedium of the food or pharmaceutical product into which said flavoringcomposition may be incorporated. It is apparent therefore, that such amedium will possess physical and chemical characteristics, and namely apH, which are a function of the nature of the varied components presentin the flavoring composition or in the above-mentioned end-products andwhich can condition the chemical form in which the α-keto-acid occurs insaid medium and produces its organoleptic effect. One has in mind inparticular the possible formation of hydrates in aqueous solution, oryet the derivatives which can result from keto-enol type tautomericequilibria. The group of compounds from which the active ingredient ofthe flavoring composition according to the invention can be selectedthus includes these potential derivatives which can be formed from saidα-keto-acids under the conditions of their utilization.

Likewise, as the edible derivatives or precursors of the α-keto-acids inthe context of the invention, one can cite in particular the ediblesalts of these acids, for example their salts of alkaline metals such assodium, lithium, magnesium, potassium or calcium, or yet their C₁ to C₄alkyl esters.

By C₁ to C₄ alkyl esters it is referred here the ester derivatives ofthe above-mentioned acids wherein the ester function contains asaturated or unsaturated, linear or branched alkyl group, having 1 to 4carbon atoms. Among others, these include the methyl and ethyl esters.

Other edible precursors of the α-keto-acids include the correspondingamino acids and namely the essential and semi-essential amino acids andtheir salts of alkaline metal. When referring here to the amino acids,one is referring more particularly to the enantiomers of these acidswhich possess an L configuration, which have a natural occurrence.

The addition according to the invention of the α-keto-acids and/or theirabove-mentioned derivatives and precursors, as active ingredients, tothe flavoring compositions and concentrates typically produces animprovement or enhancement of the impact and of the rich, creamy andfull feeling of the composition in the mouth, i.e. of the gustativeimpressions connected to the texture, volume and fullness as perceivedupon tasting these products and which are generally referred to underthe designation of the “mouthfeel” of the product. Moreover, theseeffects may be accompanied of other imparted aromatic attributes, namelythose associated with the volatile notes responsible for thecharacteristic odor and taste of a certain food product, for theflavoring of which the composition or concentrated is intended.

Now, this is a totally unexpected effect in view of the prior artknowledge, particularly as regards the literature reports related to thenatural occurrence of these compounds in cheeses. These reports do infact suggest that the said compounds may play a role in the taste of thecheese, which role may be more or less important depending on the natureof the latter, without however qualifying this role and neverassociating it to the cheeses' characteristics which relate to thetexture and more or less creamy and buttery nature thereof, e. g. theirmouthfeel.

Furthermore, as is apparent from the examples presented further on, in anumber of applications, upon the use of certain compounds among thosecited, there was observed a radical modification of the properties ofthe base composition, with a remarkable improvement not only of themouthfeel of this composition, its volume and fullness, but also, orrather, in certain aromatic notes having a choice contribution for thecomposition's organoleptic value.

However, the organoleptic effect of these α-keto-acids and theirabove-cited derivatives and precursors turns out to be even more varied.We have in fact ascertained that they could also reinforce the tastesensation of sweetness imparted by natural or artificial sweeteners.Said compounds are consequently particularly useful for flavoringfoodstuffs and beverages having a low sugar content, which are typicallysweetened with artificial substances such as Aspartame® (NutrasweetCo.), Sodium cyclamate (sodium cyclohexylsulfamate), Sucralose® (Tate &Lyle), saccharine, Acesulfam® K (Hoechst Ag) or others.

Amongst the compounds which use is the object of the invention, one cancite yet, as preferred embodiments, 2-oxo-butanoic,3-methyl-2-oxo-butanoic, 3-hydroxy-2-oxo-propanoic,2-oxo-3-phenyl-propanoic, 3-methyl-2-oxo-pentanoic,4-methyl-2-oxo-pentanoic, 4-methylthio-2-oxo-butanoic,3-mercapto-2-oxo-propanoic or 2-oxo-1H-indole-3-propanoic acids, as wellas their derivatives and precursors which can be formed or liberatethese acids in the utilization medium.

Following a preferred embodiment of the invention, the α-keto-acidsmentioned above are used in admixture with at least one amino acidselected from the group consisting of 2-amino-butanoic acid, glycine,α-alanine, norvaline, valine, aspartic acid, norleucine, leucine,isoleucine, serine, threonine, glutamic acid, phenylalanine, tyrosine,cysteine, methionine, glutamine, theanine (N-ethylglutamine),asparagine, cystine, citrulline, γ-methylene-glutamic, lysine,tryptophane, histidine, arginine and their salts of alkaline metals, forthe preparation of the flavoring compositions of the invention.

We have thus observed a synergic effect when the α-keto-acid was used inadmixture namely with the corresponding α-amino-acid, wherein the lattercan enhance the organoleptic effect of the α-keto-acid.

Preferably, these flavoring compositions contain the above-mentionedamino acid in a weight proportion comprised between 0.5 and 5, and morepreferably between 0.5 and 2 times that of the α-keto-acid. Generally,the global weight of the amino acids, when several are present, relativeto that of the α-keto-acid, or of the mixture of α-keto-acids present,will fall within the above-indicated relative proportions.

The proportions in which the above-mentioned active ingredients, i.e.the α-keto-acids and their cited edible derivatives and precursors, arepresent in the flavoring compositions of the invention can vary in awide range of values, which is dependent on the nature of the otheringredients in said composition, as well as on the organoleptic effectthat it is desired to achieve. By way of example, active ingredientconcentrations of the order of 0.01 to 10% by weight, or even higher,relative to the weight of the composition, can typically be cited.

Another object of the invention is a process for the preparation of aflavoring composition such as described previously, characterized inthat there is added to a mixture of one or more flavoring ingredients ofnatural or synthetic origin, together with current solvents oradjuvants, an active ingredient selected from the group consisting ofthe α-keto-acids, their edible derivatives and precursors defined above,or yet the mixtures of two or more of these compounds.

According to a particular embodiment of this process, said activeingredient comprises one or several α-keto-acids obtained via enzymaticconversion of the corresponding α-amino-acids, by means of an enzymaticsystem capable of converting the latter, at least partially, into thecorresponding α-keto-acids.

According to an even more particular embodiment of this process, saidα-amino-acids are selected from the group consisting of 2-amino-butanoicacid, glycine, α-alanine, norvaline, valine, aspartic acid, norleucine,leucine, isoleucine, serine, threonine, glutamic acid, phenylalanine,tyrosine, cysteine, methionine, lysine, tryptophane, histidine,arginine, asparagine, glutamine, cystine, citrulline, theanine,γ-methylene-glutamic acid and their salts, namely those of alkalinemetals.

By flavoring ingredients it is meant here any natural or syntheticorigin essential oils of current use for flavoring food products and ofwhich many examples can be found in reference textbooks such as forexample the book of P. Z. Bedoukian, Perfumery & Flavoring Synthetics,2nd ed., Elsevier, Holland (1967), or yet Fenaroli's Handbook of FlavorIngredients, 2nd ed., CRC Press, USA (1975). Of course, extracts orconcentrates of flavoring substances obtained from fruits or plants,from milk, cheeses or any other products derived from milk, are alsoexamples of flavoring ingredients in this sense.

Among the solvents and adjuvants of more current use, there can becited, by way of example, triacetine, ethanol or propylene glycol, oryet the solid carriers such as a dextrine or arabic gum.

The flavoring compositions according to the invention can be used tomodify and/or improve the taste of large variety of foods and beverages,as well as of pharmaceutical preparations, and these end-products arealso the object of the invention. As examples, there can be cited themargarines and butters, as well as yoghurts, ice-creams and frozendesserts, cheeses, milk and milk-derived products, including drinks, butalso the foodstuffs such as ready-to-eat cooked meals, soups, sauces,sweet or salty biscuits, cocktail snacks, in particular chips, or yetdesserts. The use of these compositions for the flavoring of beveragesis also advantageous, namely for carbonated drinks such as cola baseddrinks, lemonades and other.

The proportion in which said flavoring compositions can be added to thefood products mentioned above can be quite variable, since they are afunction of the nature of the product to be flavored and of the desiredorganoleptic effect. The person skilled in the art is moreover quitecapable of choosing such concentrations as a function of theseparameters, and yet of any others that may turn out to be relevant whenusing the flavoring compositions. As an indication, the compositions canbe used in proportions of the order of the concentration in which theactive ingredient is used, i. e. the α-keto-acid and/or its derivativesand precursors, or their mixtures, in the end-product, varying typicallybetween 0.001 and 10 ppm, or even 20 ppm or more, by weight, relative tothe weight of said end-product. More preferably, this concentration willbe comprised between 0.01 and 5 ppm.

As cited above, the flavoring compositions of the invention revealthemselves particularly useful for improving or enhancing the mouthfeelof the foods and beverages into which they are incorporated.

More particularly, all the food products having a low fat content, theso-called “light” or low-calorie products, can be improved, as regardstheir texture and mouthfeel, by means of the flavoring compositionaccording to the invention. The flavoring of such products presents aparticular difficulty in that, whereas it is possible to compensate moreor less successfully the gustative notes characteristic of the fatmaterials or fats, by adding the appropriate flavoring ingredients,there remains the problem related to the difficulty in reproducing, inthe lightened product, the mouthfeel and the creamy type texture whichare precisely imparted by said fats. This problem is particularly acutein the dairy products and in the light margarines, for which the use ofthe flavoring compositions according to the invention is veryadvantageous.

On the other hand, as previously cited, we have also observed that theα-keto-acids, and/or their derivatives and precursors described above,as well as the flavoring compositions containing them, are particularlyuseful for flavoring foods and drinks having a lightened sugar content,and namely those sweetened by way of Aspartame®, Sodium Cyclamate,Acesulfam® K, Sucralose®, or yet by means of mixtures of two or more ofthese compounds. It has in fact been observed that their taste becamesweeter and closer to that of the equivalent food or beverage with anormal sugar content, i.e. more natural. In this context, even moreremarkable effects were ascertained when an α-keto-acid was added incombination with one of the above-mentioned amino acids, and namely withthe corresponding amino acid. Moreover, these compounds have also beenfound to reinforce the sweetening power of natural sugars such assaccharose, fructose, glucose, maltose, etc, thus also making itpossible to reduce the amount of these sugars in the foodstuffssweetened by way of natural sugars.

It must be pointed out that, when flavoring the food products mentionedabove, the cc-keto-acids and their derivatives and precursors citedabove can also be used either on their own, or in solution in solventsof current use in the art, without being incorporated beforehand incompositions containing other flavoring ingredients. This will beparticularly the case when one or more of said keto-acids turns out tobe efficient both to impart the desired taste and to improve the creamyand full character of the foodstuff, or yet its sweet character.

It is also clear that, either the compounds, or the flavoringcompositions containing them, can be added to the edibles in a freestate or in encapsulated form, namely spray-dried, by way ofencapsulating materials of current use (proteins, gelatines, caseinates,hydrocolloides, dextrines, starch and modified starch, maltodextrines,sugars, etc) and according to the usual encapsulation techniques.

In short, the present invention also concerns a method to impart,improve or modify the taste and/or flavor of a flavoring composition orof a food product, characterized in that there is added to saidcomposition or product an organoleptically effective amount of one orseveral compounds selected from the group consisting of the α-keto-acidsin essentially pure form, as well as their edible derivatives andprecursors, which can be formed from said acids, respectively liberatesaid acids, in the utilization medium.

This is therefore a very general flavoring method, allowing thepreparation of flavored food products of varied nature and in particularof natural origin foods, or extracts thereof, enriched in theabove-mentioned compounds via addition of the latter thereto accordingto the process of the invention.

According to preferred embodiments of this method, there will be addedthe specific α-keto-acids and/or their derivatives and precursors, aswell as their mixtures, already repeatedly cited and described in detailin the examples which follow. More particularly, the process of theinvention makes it possible to improve the fatty, creamy and richcharacter, i.e. the mouthfeel of the composition or food product.According to another embodiment, it makes it possible to enhance andrender more natural the sweet taste of said composition or product, orto modify its sweetening power.

According to yet other embodiments, the process serves to impart ormodify the organoleptic character of the composition or food.

Thus, the invention provides flavoring compositions and flavoringmethods capable of imparting, improving or enhancing the organolepticcharacteristics commonly associated with the presence of fats in foods,namely the creamy texture and the fuller and more voluminous mouthfeel.In this way, the compositions according to the invention can totally orpartially replace these fat materials in a wide variety of light foods,but they can also serve to enhance the inherent organolepticcharacteristics of these fats in the foods having a normal content inthem. The foodstuffs which comprise the flavoring compositions accordingto the invention provide greater impact and a longer lasting taste inthe mouth, and possess an improved mouthfeel over the correspondingfoodstuffs not flavored according to the invention. Likewise, foodscontaining sugar or artificial replacements thereof, are improved uponaddition thereto of the α-keto-acids, their cited derivatives orprecursors, or the flavoring compositions according to the invention. Ina general fashion, the compounds according to the invention thus serveto modify or impart the organoleptic characteristics of a large varietyof flavoring compositions and food products.

Moreover, and in addition to the general applications of the activeingredients of the invention described heretofore, we have alsoestablished that the organoleptic effect of the preferred α-keto-acidsmentioned above, and of their mixtures with the corresponding aminoacids, could provide for nuanced behaviour in as much as one or anotherof these compounds revealed itself of an even more advantageous use forcertain, more specific, types of aromatic applications.

Thus, for example, for meaty type applications, particularly successfulresults were obtained with the 2-oxo-butanoic, oxalacetic,3-methyl-2-oxo-butanoic, 3-methyl-2-oxo-pentanoic, 2-oxo-glutaric and3-mercapto-2-oxo-propanoic acids. These compounds render the taste ofmeat type flavors, namely chicken, pork or beef type, rounder andjuicier, meatier, and reinforce the grilled, roasted notes of the meattype compositions, while enhancing the intensity and lastiness of theirgustative effect in the mouth. These acids seem to have a particularlymarked effect on the phenolic, pyrazinic, sulphur and aldehydicfractions, or yet on the fatty acids, of the meat type flavors. In thiscontext, preferred embodiments of the invention relate to the flavoringcompositions containing one or more of said acids, in combination withone or several compounds selected from the group consisting ofisoeugenol, 2-propylphenol, p-vinylguaiacol, 2-acetylpyrazine,2-ethyl-3,5-dimethylpyrazine, 2,3,5-trimethylpyrazine,2,3-diethyl-5-methylpyrazine, 3-ethyl-2-methylpyrazine, dimethylsulphide, dimethyl disulphide, dimethyl trisulphide, methylpropyldisulphide, 2-methylthiophenol, methional (3-methyl-thiopropanal),2-octenal, 2,4-nonadienal, 2,4-decadienal, 2,4-undecadienal,2-methoxybenzaldehyde, 2,4-dodecadienal, decenal, methyl2-furanecarboxylate, Furaneol® (4-hydroxy-2,5-dimethyl-3(2H)-furanone;origin: Firmenich SA, Geneva, Switzerland),2-ethyl-4-hydroxy-3-methyl-5(2H)-furanone (origin: Firmenich SA, Geneva,Switzerland), 2,6-dimethylbenzenethiol, 2-nonen-1-ol, 10-undecenoicacid, undecanoic acid, isodecanoic acid and isononanoic acid.

Among these flavoring compositions, those containing3-mercapto-2-oxo-propanoic acid, in combination with one or more of theabove-mentioned compounds, turned out to be particularly appropriate forthe aims of the invention.

It was also observed that an enhancement of the roasted notes of thistype of flavors could be obtained upon using 2-oxo-butanoic acid incombination with one or more compounds selected from the groupconsisting of methyl 2-furanecarboxylate, Furaneol®,2-ethyl-3,5-dimethylpyrazine, methional, 2-acetylpyrazine,2-ethyl-4-hydroxy-3-methyl-5(2H)-furanone and undecanoic and10-undecenoic acids.

Likewise, 2-oxo-glutaric acid seems to reinforce in particular the fattynotes of the meat type flavors and, to this end, it is especially usefulwhen used in combination with 2-nonen-1-ol, 2-decenal and/or2,4-decadienal. For example, flavoring compositions having a richer andfattier taste, also more roasted, grilled and crusty, were obtained byusing 3-methyl-2-oxo-pentanoic acid together with one or severalcompounds selected from the group consisting of iso-decanoic,iso-nonanoic, 10-undecenoic and undecanoic acids, Furaneol®,2,3,5-trimethylpyrazine and 2,3-diethyl-5-methylpyrazine.

In the area of vegetable type applications, particularly advantageouseffects could be obtained with 2-oxo-butanoic, 3-methyl-2-oxo-butanoic,3-methyl-2-oxo-pentanoic or yet 4-methyl-2-oxo-pentanoic acids. Forexample, enriching effects in tomato type flavors can be obtained byusing namely 2-oxo-butanoic acid together with one or more compoundsamongst the octanoic, butyric and isovalerianic acids, 5-dodecanolide,methional and dimethyl sulphide. The above-mentioned oxo-acid enhancesthe roundness and the juicy character imparted by these compounds to thetomato flavor. As for 3-methyl-2-oxo-butanoic acid, its effect is toenhance the impact and the cooked character of the flavor, typically dueto compounds such as methylmercaptan, methional, dimethyl sulphide,eugenol, 5-methylfurfural, vanillin or yet3,4-dimethyl-1,2-cyclopentanedione. 4-Methyl-2-oxo-pentanoic acid, onthe other hand, reinforces the juicy, meaty and fleshy notes andcombines well, to this effect, with one or several compounds amongstmethional, dimethyl sulphide, eugenol, orthocresol or yet guaiacol,whereas 3-methyl-2-oxo-pentanoic acid can improve the fullness andimpact of compositions and flavors containing one or more ingredientsselected from the group consisting of the sulphur compounds mentionedabove, as well as of isobutyl acetate, hexanal and 2-hexenal, linalylbenzoate, linalyl caproate and hexyl 2-butenoate.

In asparagus type flavors in particular, it was observed that2-oxo-butanoic, 3-methyl-2-oxo-butanoic and 3-methyl-2-oxo-pentanoicacids enhanced the pyrazinic, woody notes of the flavor and that theyrendered this type of flavor creamier and sweeter. Oxalacetic acid onthe other hand enhances the impact of the flavor, by reinforcing theorganoleptic effect of compounds such as dimethyl sulphide,methylmercaptan and 2-methyl-1-benzenethiol. Other α-keto-acids having apositive effect on this type of flavor are cited in the examples.

Other advantageous results were obtained with 3-methyl-2-oxo-pentanoicacid, in combination with methylmercaptan, dimethyl sulphide and3-methyl-3(5)-(methylthio)pyrazine. The compositions thus obtained wereable to particularly increase the strength and impact of the corn typeflavors. For this type of flavors, 3-methyl-2-oxo-butanoic acid is alsouseful, namely when employed in combination with sulphur ingredientssuch as dimethyl sulphide or methylmercaptan, which impact is enhancedand the sulphur character of which becomes rounder.

The use of 2-oxo-butanoic, 3-methyl-2-oxo-butanoic,3-methyl-2-oxo-pentanoic and 2-oxo-glutaric acids turns out to beparticularly advantageous for the preparation of celery type flavoringcompositions, the flavor of which becomes more powerful and rounded uponthe addition thereto of one or more of these acids. In this context,flavoring compositions containing these compounds in combination with atleast one of the compounds selected from the group consisting of2,6-nonadienol, cis-4-hexenol, hexanal, trans-2-hexenal,3-propylidenephthalide (3-propylidene-1-benzo[c]furanone),3-n-butylidenephthalide, as well as the carrot, celery, juniper andlovage essential oils, are preferred.

Moreover, the same α-keto-acids, as well as 3-mercapto-2-oxo-propanoicacid, also have a particularly rich effect on the fullness and impact ofthe cheese type flavors, namely when said acids are used in combinationwith compounds such as methional, dimethyl sulphide, methyl3-methylthiopropanoate, 2-heptanone or 2-nonanone, δ-decalactone orδ-dodecalactone, propanoic, butyric, isobutyric, pentanoic, caproic,caprilic or capric acids, and the mixtures of two or more of theabove-mentioned compounds.

Amongst the α-keto-acids of the invention, 3-methyl-2-oxo-butanoic acid,and its mixtures with valine, provide much appreciated effects when usedin flavoring compositions of the vanilla or cereal, or yet chocolatetype. It was observed, for example, that these compounds rendered thevanilla aromatic note more rounded and that they could also beadvantageously used in combination with compounds selected amongstacetylmethylcarbinol, acetylpropionyl, diacetyl,1-phenyl-1,2-propanedione, 5-dodecanolide, 4-heptanolide, 4-octanolide,3-hydroxy-2-methyl-4(4H)-pyranone, 6-methyl-3,5-heptadien-2-one,furfural, 3,4-dimethyl-1,2-cyclopentanedione, eugenol, Perou Baume oryet vanillin. More particularly, 3-methyl-2-oxo-butanoic acid rendersthe butter notes of this type of compositions even more buttery, creamyand vanilla like and enhances the creamy, coconut effect of the lactoniccompounds, while softening and rounding the burnt, brown, vanilla andphenolic notes.

Examples presented further on also illustrate the enriching effect inthe cereal or chocolate type compositions. Furthermore, it has beenobserved that this α-keto-acid (or its sodium salt), alone or inadmixture with valine, has a particularly useful bearing on Furaneol® oron 2-ethyl-4-hydroxy-3-methyl-5(2H)-furanone (origin: Firmenich SA,Geneva, Switzerland). The addition of 3-methyl-2-oxo-butanoic acid tothese compounds enhances their sweetening, caramel effect and brings amore marked fruity, strawberry and slightly pineapple note to theirtaste, while also acting on the roundness of their characteristicflavor. Said roundness is further reinforced upon adding said acid inadmixture with valine, the latter imparting an even more burnt, brownsugar and molasses character, in particular to the above-mentionedfuranone. The sweetening power of said compounds is thus enhanced. Theflavoring compositions formed of these ingredients are thereforeparticularly appreciated.

In cheese or dairy type applications, one can still cite the usefuleffects obtained with 3-(4-hydroxyphenyl)-2-oxo-propanoic acid. Thus, ithas been established that this keto-acid reinforces the fat notes andthe fruity impact of compounds such as butyric, hexanoic, octanoic,decanoic, isobutyric, isovalerianic, pentanoic, 3-phenylpropanoic orpropanoic acids, and that it can therefore be advantageously used inadmixture with one or more of these compounds. Useful effects were thusobserved with condensed milk type flavors (for example, 504 133 TH;origin: Firmenich SA, Geneva, Switzerland) or cheese type (for example,504 132 TH; origin: Firmenich SA, Geneva, Switzerland) wherein theabove-mentioned keto-acid was present in proportions comprised betweenabout 0.5 and 50 ppm by weight, relative to the weight of the flavor.

Finally, many α-keto-acids amongst those previously cited revealedthemselves useful for applications in so-called “light” beverages, i.e.artificially sweetened drinks, and more particularly those which arecola based. Some of said acids showed remarkable effects on severaltypes of artificial sweeteners, whereas other acids had more markedeffects on one or another of said sweeteners in particular. Thus,amongst the former, 3-methyl-2-oxo-butanoic acid and its mixtures withL-valine, 3-methyl-2-oxo-pentanoic acid and its mixtures withL-isoleucine and 2-oxo-glutaric acid and its mixtures with L-glutamicacid, can be cited. These compounds provide general improvement in thetaste of beverages containing Aspartame®, Sodium Cyclamate , Sucralose®,Acesulfam® K or their mixtures.

Practically all the preferred keto-acids previously cited have a usefulinfluence on the sweetening activity of Aspartame® and the examplespresented further on illustrate particularly advantageous instances oftheir use.

In addition, acids such as 2-oxo-butanoic, 4-methyl-2-oxo-pentanoic,3-hydroxy-2-oxo-butanoic (alone or in admixture with L-serine),4-(methylthio)-2-oxo-butanoic, 2-oxo-1H-imidazole-4-propanoic and3-mercapto-2-oxo-propanoic acid, are capable of enhancing and renderingmore natural the taste of drinks containing Sucralose®, whereas the twolatter-mentioned acids and 2-oxo-1H-indole-3-propanoic acid have a moremarked positive effect on the sweet taste imparted by Sodium cyclamate.

Numerous other examples of the richness and variety of organolepticeffects that can be obtained according to the invention by means of theα-keto-acids and their mixtures could be further given, namely thoserelating to the advantageous flavoring compositions which result fromusing, for example, 2-oxo-butanoic, 3-hydroxy-2-oxo-butanoic,2-oxo-glutaric and/or 3-mercapto-2-oxo-propanoic acids, in admixturewith monosodium glutamate, the taste of which is thereby improved, whencompared to the use of this compound on its own.

Thus, it will become noticeable that the scope of the present inventionis very large, the latter concerning, generally, any use as a flavoringingredient, of any compound selected from the group consisting of theα-keto-acids in essentially pure form, as well as their ediblederivatives and precursors which can be formed from said acids,respectively liberate said acids, in the utilization medium, and whichis characterized in that said selected compound is added to a flavoringcomposition or to a food product, in an amount sufficient to modify thetaste and/or flavor of said composition or of said product, and moreparticularly its fatty, creamy and rich type characteristics, its sweetor sugar type character, or, globally, its general organolepticcharacter.

The α-keto-acids used according to the invention are, in many cases,commercially available. Alternatively, they can be prepared fromcommercial products and by means of conventional type reactions.Likewise, the preparation of their alkaline metal salts and of theiralkyl esters, when the latter are not available on the market, requiresresorting to well-known reactions.

The precursors such as the amino acids cited above are also oftencommercial products.

Moreover, certain active ingredients such as the mixtures of severalα-keto-acids, optionally containing the corresponding amino acids, canbe obtained by enzymatic reactions (oxidations, deaminations ortransaminations) of natural origin protein hydrolysates. To this effect,enzymes capable of partially or totally converting the amino acidspresent can be used. Clearly, mixtures of α-keto-acids can also beobtained in this manner, for example through the combined action of anoxidase and a catalase on a mixture of the corresponding amino acids.Depending on the activity and specificity of the enzyme, the nature ofthe starting amino acids mixture, and the duration of the enzymaticreaction, the conversion of the starting mixture may be complete,leading to a mixture of the corresponding cc-keto-acids, or onlypartial, providing then a mixture of amino acids and α-keto-acids, thisonce the enzymatic system has been separated. It is clear that aseparation is however unnecessary when the latter is a denatured enzymesystem having no harmful effects on the organoleptic properties of themixture, and the latter can then be used as obtained as flavoringcomposition according to the invention.

Following an example of enzymatic preparation of a mixture ofα-keto-acids, we proceeded as follows: there were mixed, in equivalentmolar proportions (0.1 mmole of each), L-methionine, L-phenylalanine,L-leucine, L-tryptophane and L-isoleucine. This commercial origin aminoacid mixture was then enzymatically converted in aqueous solution, underthe following reaction conditions:

pH˜7.2 (by means of 6 ml of sodium pyrophosphate 0.05 M)

6 mg of L-amino-acid oxidase (E.C. 1.4.3.2, Bothrops Atrox; origin:Sigma Chemical Co.)

0.1-1 mg of ox liver catalase (origin: Fluka 60632)

slight air (or oxygen) flow

temperature: 37° C.

reaction time: 12-48 h

After 48 h of reaction, a thin layer chromatography analysis indicated a100% conversion of the cited amino acids into the correspondingα-keto-acids. The reaction product was then pasteurized to denature theenzymes, centrifuged and concentrated to provide a mixture containingequivalent amounts of 4-(methylthio)-2-oxo-butanoic,2-oxo-3-phenylpropanoic, 4-methyl-2-oxo-pentanoic,2-oxo-1H-indole-3-propanoic and 3-methyl-2-oxo-pentanoic acids.

The invention will now be described in further detail by way of thefollowing examples, wherein the α-keto-acids used according to theinvention are designated by the numbers indicated in the tablehereinafter:

TABLE Compound Corresponding number Glyoxylic acid Compound 12-Oxo-propanoic acid Compound 2 2-Oxo-butanoic acid Compound 33-Methyl-2-oxo-butanoic acid Compound 4 3-Methyl-2-oxo-pentanoic acidCompound 5 4-Methyl-2-oxo-pentanoic acid Compound 63-Hydroxy-2-oxo-propanoic acid Compound 7 3-Hydroxy-2-oxo-butanoic acidCompound 8 Oxalacetic acid Compound 9 2-Oxo-glutaric acid Compound 102-Oxo-3-phenyl-propanoic acid Compound 113-(4-Hydroxyphenyl)-2-oxo-propanoic acid Compound 122-Oxo-1H-indole-3-propanoic acid Compound 134-(Methylthio)-2-oxo-butanoic acid Compound 145-Guanidino-2-oxo-pentanoic acid Compound 15 6-Amino-2-oxo-hexanoic acidCompound 16 2-Oxo-1H-imidazo1e-4-propanoic acid Compound 173-Mercapto-2-oxo-propanoic acid Compound 18 3-Methyl-2-oxo-hexanoic acidCompound 19 3-Methyl-2-oxo-heptanoic acid Compound 20

Compounds 19 and 20, which are not available commercially, as well astheir methyl esters, were prepared by means of conventional reactions,according to the following scheme:

In addition, in these examples, the concentrations of the ingredientsindicated in the tables are always cited in parts by weight ofingredient, relative to the weight of the evaluated end-product, whetherit is a saline or sugar aqueous solution, or a ready-to-eat foodproduct.

EMBODIMENTS OF THE INVENTION EXAMPLE 1

Butter Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to J.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I J Baseflavor* 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 Compound 3 —0.3 — — — — — — — — Compound 4 — — 0.3 — — — — — — — Compound 5 — — —0.3 — — — — — — Compound 7 — — — — 0.3 — — — — — Compound 10 — — — — —0.3 — — — — Compound 11 — — — — — — 0.3 — — — Compound 12 — — — — — — —0.3 — — Compound 14 — — — — — — — — 0.3 — Compound 18 — — — — — — — — —0.3 *butter type, 504.131 CE; origin: Firmenich SA, Geneva, Switzerland

The saline solutions thus obtained were submitted, for evaluation on ablind test, to a panel of expert flavorists, composed of at least tenindividuals.

The result of this evaluation showed that the solutions containingcompositions B to J were preferred by a majority of flavorists, relativeto that of base composition A, the solutions containing compositions Cto D, H and J having been particularly appreciated. According to theflavorists, the addition of the compounds mentioned in the table to thebase flavor had as an effect to enhance the creamy character of thelatter and to reinforce its roundness, rendering the taste of thisflavor closer to that of natural butter. This improvement of theflavor's mouthfeel was moreover particularly marked in composition E.

Thus, this composition E was then retaken and serine was added to it, ata rate of 0.15 ppm, 0.3 ppm and 0.6 ppm by weight, relative to theweight of the saline solution, to prepare three novel solutions whichwere then submitted, together with that of composition E, for evaluationon a blind test, to the same panel of expert flavorists. Once more, thelatter had to indicate their preference concerning the organolepticproperties of the four solutions. According to their unanimous opinion,the novel solutions containing the compositions modified by means of theserine, had an even creamier character than that of the solutioncontaining composition E, and their animal note was better covered.Their taste was also judged to be longer lasting in the mouth.

EXAMPLE 2

Flavoring of Margarines

To a commercial “low fat” margarine (Sobluma Minical, 40% fat; origin:Migros, Switzerland) there were added the flavoring compositionsaccording to the invention containing the following ingredients, in theproportions indicated hereinafter:

Composition (ppm) Ingredient A B C D Butter type flavor * 1200 1200 12001200 Compound 7 0.4 0.4 0.4 0.4 Serine — 0.2 0.4 0.8 * 504.131 CE;origin: Firmenich SA, Geneva, Switzerland

There were thus obtained 4 samples of flavored margarine, which werethen evaluated on a blind test by a panel of expert flavorists andcompared to a base sample containing 1200 ppm by weight of the buttertype base flavor mentioned above, relative to the weight of margarine.

The results of these evaluations showed that the samples flavored bymeans of the compositions A to D according to the invention were alwayspreferred to said base sample, as regards their mouthfeel. According tothe flavorists, the sample containing composition A had an enhancedtaste of fresh butter, fatter and richer than that of the base sample,while the creamy character of the margarine containing composition B waseven more pronounced, relative to that of the sample flavored by meansof composition A. On the other hand, the occurrence of even creamier andfattier notes, recalling melted butter, could be noticed in the samplesof margarine flavored with composition C and those which containedcomposition D were almost too creamy, very full and with an enhancedmouthfeel.

Similar tests were carried out with a commercial margarine far richer infat (Mibona Classic, 83% fat; origin: Migros, Switzerland), to whichthere were added the compositions cited hereinafter:

Composition (ppm) Ingredient E F G H Butter type flavor * 1000 1000 10001000 Compound 7 0.4 0.4 0.4 0.4 Serine — 0.2 0.4 0.8 * 504.131 CE;origin: Firmenich SA, Geneva, Switzerland

When the four samples of flavored margarine were evaluated under theconditions mentioned above and compared to a base sample flavored solelyby means of the butter type flavor cited (1000 ppm), similarorganoleptic effects to those mentioned above were observed.Furthermore, the flavorists indicated that the incorporation of serine,in addition to the 3-hydroxy-2-oxo-propanoic acid, not only enhanced thecreamy character of the margarine and prolonged its impact in the mouth,but also allowed better disguising of the animal note of the flavor,thus rendering its taste more balanced and more like that of freshbutter.

EXAMPLE 3

Cheese Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to K.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I J K Baseflavor* 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 Compound3 — 0.5 — — — — — — — — — Compound 4 — — 0.5 — — — — — — — — Compound 5— — — 0.5 — — — — — — — Compound 6 — — — — 0.5 — — — — — — Compound 7 —— — — — 0.5 — — — — — Compound 10 — — — — — — 0.5 — — — — Compound 12 —— — — — — — 0.5 — — — Compound 13 — — — — — — — — 0.5 — — Compound 14 —— — — — — — — — 0.5 — Compound 18 — — — — — — — — — — 0.5 *cheese type,504.132 CE; origin: Firmenich SA, Geneva, Switzerland

The saline solutions thus obtained were submitted for evaluation on ablind test to a panel of expert flavorists composed of at least tenindividuals. The results of this evaluation showed that the solutionscontaining compositions B to K were preferred by a majority offlavorists, relative to that of base composition A. In their opinion,they all possessed an enhanced creamy character and had better impact inthe mouth than the base solution. This improving effect on the mouthfeelof the flavor was, moreover, particularly marked in compositions C, D,G, H and K.

EXAMPLE 4

Condensed Milk Type Flavoring Compositions

Solutions in spring water were prepared with the following ingredients,added to the water in the proportions indicated.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I J Baseflavor* 1000 1000 1000 1000 1000 1000 1000 1000 1000 1000 Compound 3 —0.5 — — — — — — — — Compound 4 — — 0.5 — — — — — — — Compound 5 — — —0.5 — — — — — — Compound 7 — — — — 0.5 — — — — — Compound 9 — — — — —0.5 — — — — Compound 11 — — — — — — 0.5 — — — Compound 12 — — — — — — —0.5 — — Compound 14 — — — — — — — — 0.5 — Compound 18 — — — — — — — — —0.5 *condensed milk type, 504.133 CE; origin: Firmenich SA, Geneva,Switzerland

When the solutions thus obtained were submitted for evaluation on ablind test to a panel of expert flavorists, who were expected topronounce themselves on their preference with regard to the organolepticqualities thereof, a clear preference for those containing compositionsB, C, E, G and J emerged. The taste of these solutions was judgeddistinctly better than that of the solution containing the base flavor,fuller and having more impact in the mouth. Furthermore, in theflavorists' opinion, all the solutions B to J were preferred to the basesolution for their rounder and more full-bodied character, but the fivesolutions mentioned above presented the best mouthfeel and a morenatural character.

EXAMPLE 5

Flavoring of a Cola Based Drink

Flavored samples of a cola based beverage were prepared by adding to acommercial “light” cola the following ingredients, in the proportionsindicated:

TABLE Flavored sample (ppm) Ingredient A B C D E F G H I J K Compound 30.03 — — — — — — — — — — Compound 4 — 0.03 — — — — — — — — — Compound 5— — 0.03 — — — — — — — — Compound 6 — — — 0.03 — — — — — — — Compound 7— — — — 0.03 — — — — — — Compound 9 — — — — — 0.03 — — — — — Compound 10— — — — — — 0.03 — — — — Compound 11 — — — — — — — 0.03 — — — Compound12 — — — — — — — — 0.03 — — Compound 14 — — — — — — — — — 0.03 —Compound 18 — — — — — — — — — — 0.03

The samples thus obtained were evaluated on a blind test by a panel ofexpert flavorists, with regard to the commercial product.

The panel judged that all the samples A to K had a clearly enhancedgustative impact relative to the commercial product, giving a rounderand fuller impression, more natural and closer to the taste of anon-light Coca Cola. These effects were particularly noticeable insamples A, C, D and F to I, which were preferred.

Similar tests were carried out with a commercial Coca Cola which was notlightened in sugar, to which there were added, at a rate of 0.04 ppm,the compounds 3, 5, 6, 9, 10, 11 and 12. It was then ascertained thatthe addition of the latter also improved the taste of this product,provoking a fuller sensation in the mouth, with more body and volume.This mouthfeel improvement was more marked in this case with compounds3, 6, 9, 10 and 12.

EXAMPLE 6

Flavoring of an Orange Drink

Flavored samples of a drink having an orange taste were prepared byadding to a commercial product (Fanta® Orange) the followingingredients, in the proportions indicated:

TABLE Flavored sample (ppm) Ingredient A B C D Compound 5 0.06 — — —Compound 6 — 0.06 — — Compound 9 — — 0.06 — Compound 10 — — — 0.06

The samples thus obtained were evaluated on a blind test by a panel ofexpert flavorists, relative to the commercial product.

The result of this evaluation showed that all the flavored samples werepreferred to the commercial product by a majority of flavorists.Furthermore, sample B was unanimously selected as being the best, fromthe point of view of the mouthfeel and for its more natural and sweetertaste.

EXAMPLE 7

Flavoring of a Lemonade

A commercial origin lemonade (Henniez® Fruitastic Citronette) wasflavored by adding thereto the following ingredients, in the proportionsindicated:

TABLE Flavored sample (ppm) Ingredient A B C D E Compound 3 0.06 — — — —Compound 6 — 0.06 — — — Compound 9 — — 0.06 — — Compound 10 — — — 0.06 —Compound 12 — — — — 0.06

The samples thus obtained were evaluated on a blind test by a panel ofexpert flavorists, relative to the commercial product.

The result of this evaluation showed that all the flavored samples werepreferred to the commercial product by a majority of flavorists. Inaddition, samples B and C were particularly preferred for their morenatural taste and better impact in the mouth.

EXAMPLE 8

Flavoring of a Beer

To a commercial beer without alcohol (Moussy ® Switzerland) there wereadded the following ingredients, in the proportions indicated, toprepare flavored beers.

TABLE Flavored sample (ppm) Ingredient A B C D E F Compound 3 0.06 — — —— — Compound 5 — 0.06 — — — — Compound 6 — — 0.06 — — — Compound 9 — — —0.06 — — Compound 10 — — — — 0.06 — Compound 11 — — — — — 0.06

When the thus obtained flavored samples were compared on a blind test,by a panel of expert flavorists, with the commercial beer having noalcohol, a clear preference for the flavored beers emerged, the latterhaving been judged to possess a rounder and fuller taste than that ofthe base beer, such that the impact in the mouth of the flavored beerswas judged far more similar to that of a beer having a normal content inalcohol. Moreover, these effects were at their best in samples C and E.

EXAMPLE 9

Vanilla Type Flavoring Compositions

To an aqueous solution having a 10% sugar content there were added thefollowing ingredients, in the proportions indicated, to preparedflavored solutions containing the flavoring compositions A to G.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G Base flavor*100 100 100 100 100 100 100 Compound 4 — 1.0 — — — — — Compound 5 — —1.0 — — — — Compound 7 — — — 1.0 — — — Compound 11 — — — — 1.0 — —Compound 13 — — — — — 1.0 — Compound 14 — — — — — — 1.0 *vanilla type,502.807 A; origin: Firmenich SA, Geneva, Switzerland

The solutions thus obtained were then submitted for evaluation on ablind test to a panel of expert flavorists, composed of at least tenindividuals.

According to the flavorists' opinion, the solutions containing thecompositions B to G all possessed a creamier character and produced alonger lasting gustative effect than that of the base composition A.This mouthfeel improvement of the base flavor was particularly markedfor the solutions which contained compositions B, D and G, whereas thevanilla pod type note of compositions C and E appeared reinforcedrelative to that of composition A.

It was also observed that the addition, to the base flavor, of compounds19 or 20, or of their methyl ester, in concentrations of the order of0.5 to 5 ppm by weight, also improved the taste of the base flavor,rendering it softer, more milky and vanilla like.

EXAMPLE 10

Chocolate Type Flavoring Compositions

To an aqueous solution having a 10% sugar content there were added thefollowing ingredients, in the proportions indicated, to prepare flavoredsolutions containing the flavoring compositions A to H.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H Baseflavor* 100 100 100 100 100 100 100 100 Compound 2 — 1.0 — — — — — —Compound 3 — — 1.0 — — — — — Compound 4 — — — 1.0 — — — — Compound 6 — —— — — — — Compound 11 — — — — — 1.0 — — Compound 13 — — — — — — 1.0 —Compound 14 — — — — — — — 1.0 *chocolate type, 503.313 A; origin:Firmenich SA, Geneva, Switzerland

The solutions thus obtained were submitted for evaluation on a blindtest to a panel of expert flavorists, who had to indicate theirpreferences with regard to the organoleptic properties of the solutions.The results of this evaluation brought out the remarkable changesoperated on the organoleptic profile of the base flavor, particularly inthe case of compositions C, D, E, F, G and H, the solutions of which hada far stronger taste, more reminiscent of the black chocolate taste,more powdery and fuller, and even more alcoholic than that of thesolution of composition A. In addition, they had a far creamier andricher impact in the mouth.

EXAMPLE 11

Coffee Type Flavoring Compositions

To an aqueous solution having a 10% sugar content there were added thefollowing ingredients, in the proportions indicated, to prepare flavoredsolutions containing the flavoring compositions A to F.

TABLE Flavoring composition (ppm) Ingredient A B C D E F Base flavor *100 100 100 100 100 100 Compound 2 — 1.0 — — — — Compound 3 — — 1.0 — —— Compound 4 — — — 1.0 — — Compound 7 — — — — 1.0 — Compound 13 — — — —— 1.0 * coffee type, 502.334 A; origin: Firmenich SA, Geneva,Switzerland

These solutions were evaluated on a blind test by a panel of expertflavorists, the majority of whom indicated a preference for thesolutions containing compositions B to F. More particularly, they judgedthat the solutions of compositions B, D and E had an enhanced creamy andbutter character relative to that of the base solution, with a note offreshly ground coffee and a long lasting mouthfeel effect. On the otherhand, the additional notorious change in the solutions of compositions Cand F, relative to that of the base composition A, was the enhancementof the roast, burnt, black coffee type note, with greater intensity ofthe “expresso” type character.

EXAMPLE 12

Flavoring of a Tea Based Beverage

To a commercial tea beverage (Lipton® Light, sweetened with Aspartame ®)there were added the following ingredients, in the proportionsindicated, to prepare flavored drinks.

TABLE Flavored sample (ppm) Ingredient A B C D E F G Compound 5 1.2 — —— — — — Compound 6 — 1.2 — — — — — Compound 7 — — 1.2 — — — — Compound11 — — — 1.2 — — — Compound 12 — — — — 1.2 — — Compound 13 — — — — — 1.2— Compound 18 — — — — — — 1.2

When the flavored drinks thus obtained were compared on a blind test bya panel of expert flavorists with the commercial tea, there appeared adistinct preference for the flavored drinks, which were judged of a lessbitter and rounder taste, the powdery note of the Aspartame ® havingalso being reduced relative to that of the commercial tea, with theresult that the sweetness of the latter was enhanced. Such effects wereparticularly marked in samples A to C and D, the taste of which wascloser to that of a normally sugared drink than that of the commercialtea. In addition, drink A had acquired a fruity, blackberry type note,whereas sample F possessed an interesting fermented, dry leaf character.

EXAMPLE 13

Meat Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to K.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I J K Baseflavor* 20 20 20 20 20 20 20 20 20 20 20 Compound 2 — 0.5 — — — — — — —— — Compound 3 — — 0.5 — — — — — — — — Compound 6 — — — 0.5 — — — — — —— Compound 7 — — — — 0.5 — — — — — — Compound 9 — — — — — 0.5 — — — — —Compound 11 — — — — — — 0.5 — — — — Compound 12 — — — — — — — 0.5 — — —Compound 13 — — — — — — — — 0.5 — — Compound 14 — — — — — — — — — 0.5 —Compound 18 — — — — — — — — — — 0.5 *roastbeef type, 504.079 TH; origin:Firmenich SA, Geneva, Switzerland

The saline solutions thus obtained were submitted, for evaluation on ablind test, to a panel of expert flavorists, composed of at least tenindividuals. The result of this evaluation showed that the solutionscontaining the compositions B to K were systematically preferred by amajority of flavorists, relative to that of the base composition A. Intheir opinion, they all possessed an enhanced meaty character, a richertaste and better impact on the mouth than that of the base solution A.This is apparent from the following table which summarizes theevaluations in terms of organoleptic descriptors, relative to the basesolution.

TABLE Composition Taste B more meaty and full, more roasty C more fatty,more body, more balanced D more grilled, meaty and rounder E more fattyand grilled, more crusty F more fatty and juicy, bloody G more roasty,round and tallow H more body, more fatty and meaty I more roasty, richand oily J more fatty, rich, crusty and full, more body K more grilled,tallow

Compositions B, D to F and J were particularly liked.

EXAMPLE 14

Meat Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to H.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H Baseflavor* 50 50 50 50 50 50 50 50 Compound 1 — 0.5 — — — — — — Compound 6— — 0.5 — — — — — Compound 7 — — — 0.5 — — — — Compound 11 — — — — 0.5 —— — Compound 13 — — — — — 0.5 — — Compound 14 — — — — — — 0.5 — Compound18 — — — — — — — 0.5 *beef broth type, 504.080 TH; origin: Firmenich SA,Switzerland

The saline solutions thus obtained were submitted, for evaluation on ablind test, to a panel of expert flavorists, composed of at least tenindividuals. The result of this evaluation showed that the solutionscontaining the compositions B to H were systematically preferred by amajority of flavorists, relative to that of the base composition A. Intheir opinion, they all possessed a rounder and more full-bodiedcharacter, a richer taste and a better impact on the mouth than that ofthe base solution. This is apparent from the following table whichsummarizes the evaluations in terms of organoleptic descriptors,relative to the base solution.

TABLE Composition Taste B more fatty, oily and full C more animal,enhanced meaty notes, pork D animal, tallow, meaty, more impact E morefatty and roasty, more meaty, copious F softer and more oily, meaty,copious and fuller G more roasty, fuller and less tallow H more meaty,brothy, roasty and full

The flavorists showed a particular interest in compositions C, F andmore especially H.

EXAMPLE 15

Meat Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to G.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G Base flavor*100 100 100 100 100 100 100 Compound 2 — 0.5 — — — — — Compound 4 — —0.5 — — — — Compound 6 — — — 0.5 — — — Compound 12 — — — — 0.5 — —Compound 13 — — — — — 0.5 — Compound 18 — — — — — — 0.5 *savory beeftype, 504.081 TH; origin: Firmenich SA, Geneva, Switzerland

The saline solutions thus obtained were submitted, for evaluation on ablind test, to a panel of expert flavorists, composed of at least tenindividuals. The result of this evaluation showed that the solutionscontaining the compositions B to G were systematically preferred by amajority of flavorists, relative to that of the base composition A. Intheir opinion, they all possessed an enhanced meaty character, a richerand fattier taste and better impact on the mouth than that of the basesolution. This is apparent from the following table which summarizes theevaluations in terms of organoleptic descriptors, relative to the basesolution.

TABLE Composition Taste B more meaty and brothy, slightly more fatty,more impact C richer, less sulphury, fattier and fuller, more impact andbetter balanced D more juicy, broth, more full and roasty, more impact Emore meaty, roasty, full, sulphur notes flatened F more broth, meaty,rich and full, bloody G more meaty, full, juicy, sulphury

Compositions C and E were particularly appreciated.

EXAMPLE 16

Flavoring of an Instant Dessert

A “light” instant dessert was prepared with the following ingredients:

Ingredients Parts by weight Sugar 69.13 Dariloid ® QH ¹⁾ 3.00 Sodiumpyrophosphate in powder 1.30 Calcium sulphate dihydrated 0.70 Salt 0.40Food coloring 0.47 Total 75.00 ¹⁾ alginate; origin: Kelco InternationalGmbH, Germany

In an appropriate vessel the above-mentioned ingredients wereincorporated into 480 ml of cold milk. The mixture was stirred in anelectric mixer during 3 minutes and then poured into dessert cups. Thelatter were put into the refrigerator for 15 minutes.

At the same time, flavored desserts according to the invention wereprepared, by adding to the above-mentioned base dessert, before itsplacement in the refrigerator, the following ingredients, in theproportions indicated.

Flavored dessert (ppm) Ingredient A B C D Flavor * 1300 1300 1300 1300Compound 4 0.70 0.70 0.70 0.40 Valine — 0.35 0.70 0.80 * condensed milktype, 504.133 CE; origin: Firmenich SA, Geneva, Switzerland

These four desserts were then compared on a blind test, by a panel ofexpert flavorists, with the base dessert flavored by means of 1300 ppmof the condensed milk flavor mentioned above. The flavorists indicatedan unanimous preference for the flavored desserts A to D, the taste ofwhich was judged more buttery and full, as is apparent from thefollowing table which summarizes the evaluations in terms oforganoleptic descriptors, relative to the base dessert containing onlythe flavor.

TABLE Dessert Taste A less burnt, creamier, fermented, rum and vanilla,volatile note more full-bodied, less caramel and more butter B morevanillin, caramel and buttery C softer and fuller, more creamy andbuttery, vanilla D more sugared and buttery, melted butter, slightlyhazelnut

EXAMPLE 17

Vegetable Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the proportions indicated, to prepare flavored solutionscontaining the flavoring compositions A to E.

TABLE Flavoring composition (ppm) Ingredient A B C D E Base flavor * 200200 200 200 200 Compound 6 — 0.6 — — — Compound 7 — — 0.6 — — Compound13 — — — 0.6 — Compound 14 — — — — 0.6 * asparagus type, 503.484 T;origin: Firmenich SA, Geneva, Switzerland

The solutions thus obtained were submitted, for evaluation on a blindtest, to a panel of expert flavorists, composed of at least tenindividuals.

In the opinion of the flavorists, the solutions containing thecompositions B to D all possessed an enhanced vegetable character andmore typical of asparagus than that of the solution containingcomposition A, and the solution of composition E in particular had farmore impact and improved mouthfeel.

Similar tests were carried with celery type compositions, prepared withthe following ingredients:

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I J Baseflavor* 200 200 200 200 200 200 200 200 200 200 Compound 2 — 0.6 — — — —— — Compound 3 — — 0.6 — — — — — Compound 6 — — — 0.6 — — — — Compound 7— — — — 0.6 — — — Compound 9 — — — — — 0.6 — — Compound 11 — — — — — —0.6 — Compound 12 — — — — — — — 0.6 — Compound 13 — — — — — — — — 0.6 —Compound 14 — — — — — — — — — 0.6 *celery type, 503.071 T; origin:Firmenich SA, Geneva, Switzerland

Once more, the flavorists showed a preference for compositions B to Jrelative to composition A, with a particular preference for compositionC the taste of which had become stronger, more meaty, terpenic andwoody.

EXAMPLE 18

Flavoring of Orange Juice and of Orange Type Flavoring Compositions

To a base orange juice, obtained by simple dilution of a commercialorigin concentrate, there were added the following ingredients, in theproportions indicated, to prepare flavored samples.

TABLE Flavored sample (ppm) Ingredient A B Compound 5 1.0 — Compound 11— 0.5

The orange juices thus obtained were then submitted, together with thebase juice, to a panel of expert flavorists, for a blind evaluation.

According to the flavorists, samples A and B had a sweeter and fullertaste, less metallic than that of the base juice, sample A in particularalso having more body. These effects were observed through a whole rangeof concentrations tested.

On the other hand, the addition of 1 ppm of compound 11 to a finishedflavor of the orange type (705 169.01 A; origin: Firmenich SA, Geneva,Switzerland) provided an improvement in the juicy character, in thefruity, sweet note of the flavor and enhanced its volume and impact inthe mouth. In the flavorists' opinion, the compound of the inventionproduced a particularly marked effect on the aldehydic notes of theflavor, softening them, and enhanced in a much appreciated manner thefruity, citronella characters imparted by such compounds as citral andcitronellal.

EXAMPLE 19

Flavoring of Bouillons

A base meat bouillon was prepared by means of a Star Sapore Lieve(origin: Star SpA, Brianza, Italy) type cube. To this base bouillonthere was added, on the one hand, 0.5 ppm of 3-methyl-2-oxo-pentanoicacid (compound 5) to prepare a novel bouillon A and, on the other hand,the same amount of this compound and 1.5 ppm of isoleucine to prepare anew broth B.

The three bouillons were then evaluated on a blind test by a panel ofexpert flavorists, who were asked to indicate their preference from thepoint of view of the organoleptic properties of the evaluated products.

A majority of flavorists preferred bouillons A and B to the basebouillon, the taste of bouillon A having been judged more meaty, fulland umami, and that of bouillon B having a more pronounced meatcharacter, with more balanced fatty notes.

Similar tests were carried out with a vegetable type base soup, preparedby means of a Knorr® Gusto Vegetale cube (origin: CPC Italia SpA, Milan,Italy). To this base soup there was added 1 ppm of3-mercapto-2-oxo-propanoic acid (compound 18) to prepare a novel soup C.In parallel, a new bouillon D was prepared by adding to the basebouillon the same amount of this compound and 2 ppm of cysteine (in theform of its salt with HCl).

Upon the evaluation on a blind test of bouillons C and D and the basebouillon, a clear preference for the first two was ascertained, bouillonD being the most appreciated.

EXAMPLE 20

Flavoring of “Cantadou” Type Cheeses

Cheeses flavored according to the invention were prepared by adding to abase cheese of the “Cantadou-ail, fines herbes” (garlic, fine herbs;origin: Migros, Switzerland) the following ingredients, in theproportions indicated.

Flavored cheese (ppm) Ingredient A B C D Compound 18 0.80 0.80 0.80 0.80Cysteine — 0.40 0.80 1.60

These four cheeses were then compared to the base cheese by a panel ofexpert flavorists, on a blind test. The effect of adding theabove-mentioned ingredients springs out in a clear manner from the tablehereinafter, which summarizes the evolutions in terms of organolepticdescriptors, relative to the base cheese.

TABLE Cheese Taste A more acidic, more fatty, garlic note slightlycovered B more fatty, soft, creamy, longer lasting in the mouth C almostmayonnaise, creamy, more savoury, glutamate D mayonnaise, almostcooked-meaty, heavy, herbal

This effect of enhancing the creaminess of the cheese, to a point ofbecoming almost oily, was also observed with two other types of“Cantadou” on which similar tests were carried out, the results of whichare summarized hereinafter.

Thus, to a “Cantadou-curry” (origin: Migros) there were added thefollowing ingredients:

Flavored cheese (ppm) Ingredient F F G H Compound 18 0.80 0.80 0.80 0.80Cysteine — 0.40 0.80 1.60

Upon evaluation of the four novel cheeses, relative to the base cheese,the following comments were made:

TABLE Cheese Taste E less chalky, more acidic, more mouthfeel, morecurry and slightly less fenugreek F less acidic, more creamy , moremouthfeel G more savoury, more fatty-creamy, enhanced caramel and cuminnote, more mouthfeel H pasty, very heavy and buttery, curry noteslightly crushed

Finally, to a “Cantadou-raifort” (horseradish ; origin: Migros), thefollowing ingredients were added:

Flavored cheese (ppm) Ingredient I J K L Compound 18 0.80 0.80 0.80 0.80Cysteine — 0.40 0.80 1.60

When these four novel cheeses were evaluated, relative to the basecheese, the following comments were expressed:

TABLE Cheese Taste I stronger, more piquant, more acidic J even morepiquant than I, creamier, slightly melted cheese K piquant tonality evenmore exhalted and covering the creamy character, slightly sulphury Lmore piquant, attenuated cheese connotation, slightly sulphury

In the latter case, the addition of the above-mentioned ingredientsengenders an increase in the piquant/spicy character of the base cheese,together with an enhanced mouthfeel, but which is not so apparent as inthe other two types of “Cantadou” mentioned higher up. In fact, thepiquant and fresh notes of the horseradish are those which arereinforced in this case.

EXAMPLE 21

Cereal Type Flavoring Compositions

The following ingredients were added to spring water, in the proportionsindicated, to prepare flavored solutions containing the flavoringcompositions A to H.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H Baseflavor* 100 100 100 100 100 100 100 100 Compound 3 — 1.0 — — — — — —Compound 4 — — 1.0 — — — — — Compound 5 — — — 1.0 — — — — Compound 6 — —— — 1.0 — — — Compound 11 — — — — — 1.0 — — Compound 12 — — — — — — 1.0— Compound 13 — — — — — — — 1.0 *cereal type, 502.749 A; origin:Firmenich SA, Geneva, Switzerland

The solutions thus obtained were then submitted for evaluation on ablind test to a panel of expert flavorists, who had to indicate theirpreferences from the point of view of the organoleptic qualities ofthese solutions. The results of this evaluation brought out themodifications in the organoleptic profile of the base flavor, inparticular in the case of compositions D, E, F, G and H, the solutionsof which had an enhanced chocolate character and a better impact in themouth.

EXAMPLE 22

Honey Type Flavoring Compositions

To a 10% sugar solution there were added the following ingredients, inthe proportions indicated.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H I Baseflavor* 100 100 100 100 100 100 100 100 100 Compound 3 — 1.0 — — — — — —— Compound 5 — — 1.0 — — — — — — Compound 6 — — — 1.0 — — — — — Compound7 — — — — 1.0 — — — — Compound 11 — — — — — 1.0 — — — Compound 12 — — —— — — 1.0 — — Compound 13 — — — — — — — 1.0 — Compound 18 — — — — — — —— 1.0 *honey type, 503.666 A; origin: Firmenich SA, Geneva, Switzerland

When the solutions thus obtained were submitted for evaluation on ablind test to a panel of expert flavorists, remarkable changes in theprofile of the base flavor were observed. Thus, solutions B, D and F nowpossessed a taste wherein the caramel type character was distinctlyreinforced relative to that of the base flavor, whereas compositions E,G and H had an increased floral character and their tonality reminiscentof the typical taste of phenylacetate had also become stronger.

EXAMPLE 23

Alcoholic Type Flavoring Compositions

The following ingredients were added to a 10% sugar solution, in theproportions indicated.

TABLE Flavoring composition (ppm) Ingredient A B C D E F G H Baseflavor* 200 200 200 200 200 200 200 200 Compound 2 — 1.0 — — — — — —Compound 3 — — 1.0 — — — — — Compound 7 — — — 1.0 — — — — Compound 10 —— — — 1.0 — — — Compound 11 — — — — — 1.0 — — Compound 14 — — — — — —1.0 — Compound 18 — — — — — — — 1.0 *rum type, 53.305 T; origin:Firmenich SA, Geneva, Switzerland

When these compositions were evaluated on a blind test, the flavoristsshowed a preference for compositions B to H relative to composition A.They indicated further that when using a base flavor of the alcoholicdrink type such as mentioned above, two types of modifications could beobserved in the profile of this flavor. For example, compositions C to Eand G, H had a more fermented character, while compositions B and F weremore phenolic than composition A.

EXAMPLE 24

Flavoring of Fruit Juices

To a blackcurrant juice, obtained by simple dilution in spring water ofa concentrated juice of commercial origin, there were added 5 ppm of2-oxo-butanoic acid (compound 3). Upon the blind evaluation of the thusflavored juice, relative to the solution of commercial juice, the panelof expert flavorists expressed a preference for the former, the taste ofwhich had a more cooked tonality, slightly jam like and liquorice.Similar tests with a raspberry juice, to which however 5 ppm of3-methyl-2-oxo-pentanoic acid (compound 5) and 5 ppm of isoleucine hadbeen added, showed that the juice flavored according to the inventionhad a far more pronounced raspberry tonality.

EXAMPLE 25

Vanillin Flavored Compositions

A base aqueous solution containing 10 ppm by weight of vanillin wasprepared. With this solution, novel solutions were obtained by addingthereto 1 ppm of compound 4 (solution A) and, respectively 1 ppm ofcompound 7 (solution B). Solutions A and B were then compared on a blindtest with the base one by a panel of expert flavorists, who preferredsolutions A and B and qualified their organoleptic character as follows,relative to that of the base solution:

TABLE Solution Taste A sweeter, creamier, enhanced mouthfeel, morepraline like, with slightlier fatty character B slightly more powdery,cardboard

Solution A was better appreciated. In addition, when the sodium salt ofcompound 4 was added, at a rate of 2 ppm, to the vanillin, similarorganoleptic effects to those observed with solution A were noted.

EXAMPLE 26

Flavoring of Chocolate Drinks

Chocolate drinks were prepared by adding 20 g of a chocolate powder ofthe Nesquick® type (Nestle) to 200 ml of skimmed milk.

To this base chocolate drink were then added the following ingredients,in the proportions indicated.

Flavored drink (ppm) Ingredient A B C D Flavor * 1500 1500 1500 1500Compound 4 1.2 1.2 — — Valine — 1.5 — — Compound 5 — — 1.2 1.2Isoleucine — — — 1.5 * Firanova ® chocolate type, 570.090 TPL 0404;origin: Firmenich SA, Geneva, Switzerland

These four drinks were then compared on a blind test by a panel ofexpert flavorists, with the base drink flavored by means of 1500 ppm ofthe chocolate flavor mentioned above. The flavorists indicated anunanimous preference for the flavored drinks A to D, the taste of whichwas judged to be creamier and more full-bodied, as is apparent from thetable hereinafter, which summarizes the evaluations in terms oforganoleptic descriptors, relative to the base drink containing only theflavor.

TABLE E Drink Taste A richer, creamier, softer in the milky notes B asA, but with an even enhanced dark chocolate character C softer milkynotes and increased creamy character D again, a reinforced darkchocolate type taste relative to C

EXAMPLE 27

Flavoring of Coffee Drinks

Drinks having a coffee taste were prepared by adding 12.5 g of a powdercoffee of the Nestlé® Cappucino type to 150 ml of non-boiling hot water.To this base coffee drink there were then added the followingingredients, in the proportions indicated.

Flavored drink (ppm) Ingredient A B C D Flavor * 1500 1500 1500 1500Compound 4 1.5 1.5 — — Valine — 1.7 — — Compound 5 — — 1.5 1.5Isoleucine — — — 1.7 * Firanova ® cappucino type, 570.092 TPL 0451;origin Firmenich SA, Geneva, Switzerland

These four drinks were then compared on a blind test by a panel ofexpert flavorists, with the base drink flavored by means of 1500 ppm ofthe coffee flavor above-mentioned. The flavorists indicated an unanimouspreference for the flavored drinks A to D, the taste of which was judgedto be smoother and giving a more persistent impression, as is apparentfrom the table hereinafter, which summarizes the evaluations in terms oforganoleptic descriptors and relative to the base drink containing onlythe flavor.

TABLE Drink Taste A richer, creamier and smoother, longer lasting effectin the mouth B as A, but with enhanced black coffee character C as A Das B

EXAMPLE 28

Chicken Type Flavoring Composition

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) Isoeugenol 1.0000 p-Vinylguaiacol0.1000 2-Acetylpyrazine 0.0050 2,3,5-Trimethylpyrazine 0.02003-Ethyl-2-methylpyrazine 0.2500 Dimethyl sulphide 2.0000 Dimethyldisulphide 0.5000 Methylpropyl disulphide 0.0015 Dimethyl trisulphide0.0100 2-Methylthiophenol 2.0000 2-Octenal 0.0050 2,4-Nonadienal 0.00502,4-Undecadienal 0.0050 2,4-Dodecadienal 0.0100

To this base solution, which had a chicken type aroma note, there wasadded, at a rate of 0.5 ppm, one of the compounds 3, 4, 5 or 10, toprepare novel flavored solutions. When the latter were tasted by a panelof expert flavorists and compared to the base solution, it becameapparent that they possessed a chicken taste of enhanced fullness andstrength, relative to the base solution. The flavorists also indicatedthat they perceived the taste of these novel solutions for a far longerperiod of time.

Moreover, similar effects were observed when the properties of a chickentype finished flavor (504 303 TH; origin : Firmenich SA, Geneva,Switzerland) were organoleptically modified by the addition, at a rateof 0.05% by weight, of one of the above-mentioned acids, or yet ofcompound 18.

EXAMPLE 29

Beef Type Meat Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) Methyl 2-furanecarboxylate 1.00Furaneol ® 0.8030 2-Ethyl-3,5-dimethylpyrazine 0.01 10-Undecenoic acidredist. 0.60 Undecanoic acid 0.165 Methional 0.035 2-Acetylpyrazine0.020 2-Ethyl-4-hydroxy-3-methyl-5(2H)-furanone 0.010 Iso-decanoic acid0.30 Iso-nonanoic acid 0.15 10-Undecenoic acid 0.502,3,5-Trimethylpyrazine 0.06 2,3-Diethyl-5-methylpyrazine 0.03

The addition of 5 ppm of compound 3, 5 or 18 to this base solution madeit possible to quite enhance the meaty and grilled character of the basecomposition, also giving it an increased impact in the mouth.

The same effect was observed upon addition of any one of theabove-mentioned acids to a finished meat type flavor (573030 P; origin:Firmenich SA, Geneva, Switzerland).

To this end, the base flavor (1000 ppm) and the novel flavor obtained byaddition of 5 ppm of acid were tasted in saline solutions such as thosepreviously mentioned, on a blind test.

EXAMPLE 30

Tomato Type Flavoring Composition

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) Octanoic acid 2.000 5-Dodecanolide0.300 Methional 0.700 5-Methylfurfural 6.000 Vanilline 0.100 Eugenol0.400 Ortho-cresol 0.020 Guaiacol 0.030 Dimethyl sulphide 25.000Methylmercaptan 0.003

With this flavored base solution, 3 novel flavored solutions wereprepared by adding thereto 5 ppm of compound 3 (solution A), 5 ppm ofcompound 4 (solution B) and 5 ppm of compound 6 (solution C).

The four solutions were then evaluated on a blind test by a panel ofexpert flavorists. The latter unanimously preferred solutions A, B and Cto the base solution, with regard to which solution A was judged to havea stronger and fuller taste, also juicier, solution B a more pronouncedcooked character and solution C was judged to be far juicier and richerin “fleshy” character. Similar effects were observed when theabove-mentioned acids were added, at a rate of 5% by weight to a tomatotype finished flavor (502022 A; origin: Firmenich SA, Geneva,Switzerland).

EXAMPLE 31

Tomato Type Flavoring Composition

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) Butyric acid 1.00 Isovalerianic acid1.50 Octanoic acid 0.60 Methional 1.30 Dimethyl sulphide 40.00Methylmercaptan 0.03 3,4-Dimethyl-1,2-cyclopentanedione 0.10 Fugenol0.40 5-Methylfurfural 6.00 Isobutyl acetate 0.90 Hexanal 1.20 2-Hexenal0.50 Linalyl benzoate 3.00 Linalyl caproate 8.00 Hexyl 2-butenoate 0.40

When 5 ppm of compound 5 were added to this base solution, there wasobtained a novel flavored solution, the tomato taste of which had fargreater impact in the mouth and was more full-bodied than that of thebase solution. This compound brought a similar modification to the tasteof a finished flavor (tomato 502224 A; origin: Firmenich SA, Geneva,Switzerland) into which said compound had been incorporated at a rate of5% by weight.

EXAMPLE 32

Cheese Type Flavoring Compositions

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) Methional 0.45 Dimethyl sufide 0.45Methyl 3-(methylthio)-propanoate 1.15 2-Heptanone 0.75 2-Nonanone 1.50δ-Decalactone 0.75 δ-Dodecalactone 1.50 Propanoic acid 27.75 Butyricacid 30.00 Isobutyric acid 4.50 Pentanoic acid 7.50 Isovalerianic acid2.25 Caproic acid 12.00 Caprylic acid 12.00 Capric acid 4.50

When 0.5 ppm of one of compounds 3, 4, 5, 10 or 18 were added to thisbase solution, an improvement in the taste and flavor of the solutionwas observed, the latter having become stronger and fuller, with alonger lasting effect in the mouth.

EXAMPLE 33

Celery Type Flavoring Composition

To a 0.5% NaCl aqueous saline solution there were added the followingingredients, in the relative proportions indicated, to prepare aflavored base solution containing the flavoring composition formed ofthese ingredients.

Ingredients Parts by weight (ppm) 2,6-Nonadienol 0.0001 cis-4-Hexenol4.0000 Hexanal 1.0000 trans-2-Hexenal 1.0000 3-Propylidene phthalide12.0000 3-n-Butylidene phthalide 0.6000 Carrot essential oil 0.8000Celery essential oil 50.0000 Juniper essential oil 5.0000 Lovage leavesessential oil 6.0000

The addition to this base composition of 0.5 ppm of one of compounds 3,4, 5 or 10 provided novel flavoring compositions having a far richer andfuller celery taste.

EXAMPLE 34

Chocolate Type Flavoring Compositions

The following ingredients were added to spring water, in the proportionsindicated, to prepare a flavored base solution containing the flavoringcomposition composed of these ingredients.

Ingredients % by weight Butyric acid 1.0 Isobutyric acid 1.02-Methylbutyric acid 1.0 Isovalerianic acid 1.0 2-Methyl-caproic acid1.0 Isobutyric aldehyde 2.0 Isovalerianic aldehyde 0.5 5-Methylfurfural2.5 Furfuryl alcohol 3.0

The addition to this base solution of compound 4, or of its sodium salt,at a rate of 3 ppm, reinforces the buttery and creamy character of thecomposition and renders it richer, while softening the aldehydic notes.

EXAMPLE 35

Caramel Milk Type Flavoring Compositions

The following ingredients were added to spring water, in the proportionsindicated, to prepare a flavored base solution containing the flavoringcomposition composed of these ingredients.

Ingredients % by weight Mixture of octanoic and decanoic acids 7.5Vanilline 7.5 δ-Decalactone 3.0 Methyl 2-furanecarboxylate 3.0 Acetoine2.5 Furaneol ® 2.0

The addition of 4 ppm of compound 4 to this solution enhances thecaramel, fudge notes of the composition, as well as the milky notes, andbrings to it increased sweetness and creaminess. Furthermore, thecaramel taste of this novel composition is distinctly longer lasting inthe mouth.

The same type of organoleptic effect was observed when adding the samecompound to a finished caramel milk type flavor (502625 A; origin:Firmenich SA, Geneva, Switzerland).

EXAMPLE 36

Flavoring Compositions of Type Cassis Sweetened With Aspartame®

A spring water, sweetened by means of 0.025% by weight of Aspartame® andcontaining 0.15% by weight of citric acid, was flavored with 50 ppm of ablackcurrant type flavor composed of the following ingredients.

Ingredients Parts by weight 3-Hexen-1-ol 5 Buchu oil 2 α-Ionone 18-Mercapto-3-p-menthanone * 15 Eugenol 2 Dimethyl sulphide 30 Maltol 50p-Hydroxyphenyl-2-butanone 30 Ethyl butyrate 75 Propyleneglycol q.s.Total 1000 * at 1% in propyleneglycol; origin: Firmenich SA, GenevaSwitzerland

Compounds 4, 13 and 17 were added to this base solution, at a rate of 5ppm, to prepare three novel flavored solutions.

A panel of expert flavorists then evaluated these solutions on a blindtest, relative to the base solution. In the flavorists' opinion, thethree novel solutions were all preferred for their far juicier andfruitier blackcurrant note, relative to that of the base solution.

The same effects were observed when the above-mentioned acids were addedat a rate of 10 ppm by weight.

Similar evaluations were carried out, in aqueous solutions sweetened bymeans of 0.025% by weight of Aspartame® and containing 0.15% of citricacid, with a finished base flavor of the blackcurrant type (50 ppm;502009 A; origin: Firmenich SA, Geneva, Switzerland), and with a mixtureof the latter with 5 ppm of compound 13 (flavor A), 5 ppm of compound 17(flavor B) or 5 ppm of compound 4 or its sodium salt (flavor C).According to the flavorists, flavors A, B and C all possessed afruitier, juicier and jam like taste, also more full-bodied and sweeter,than the base flavor. They were all preferred to the latter.

EXAMPLE 37

Raspberry Type Flavoring Compositions Sweetened with Aspartame®

A spring water, sweetened by means of 0.025% by weight of Aspartame® andcontaining 0.15% by weight of citric acid, was flavored with 100 ppm ofa raspberry type flavor composed of the following ingredients.

Ingredients Parts by weight 3-Hexen-1-ol 15 Ethyl acetate 75 α-Ionone 1Isobutyl acetate 20 Geraniol 10 p-Hydroxyphenyl-2-butanone 75Propyleneglycol q.s. Total 1000

Compounds 4, 13 and 17 were added to this base solution, at a rate of 5ppm by weight, to prepare three novel flavored solutions.

A panel of expert flavorists then evaluated these solutions on a blindtest, relative to the base solution. The flavorists preferred the threenovel solutions which were judged to have an enhanced fruity andjam-like note.

The same effects were observed when the above-mentioned acids were addedat a rate of 10 ppm by weight.

Similar evaluations were carried out, in aqueous solutions sweetened bymeans of 0.025% by weight of Aspartame® and containing 0.15% of citricacid, with a finished base flavor of the raspberry type (100 ppm;52354/A; origin: Firmenich SA, Geneva, Switzerland), and with a mixtureof the latter with 5 ppm of compound 13 (flavor A), 5 ppm of compound 17(flavor B) or 5 ppm of compound 4 or its sodium salt (flavor C).According to the flavorists, flavors A, B and C all possessed a sweeterand more jam like taste, also more full-bodied, than the base flavor andthey were all preferred to the latter.

EXAMPLE 38

Orange Type Flavoring Compositions

A spring water, sweetened by means of 0.025% by weight of Aspartame® andcontaining 0.15% by weight of citric acid, was flavored by means of 100ppm of an orange type flavor composed of the following ingredients:

Ingredients Parts by weight Acetic aldehyde 30 Hexanol 3 Dodecanol 6Ethyl butyrate 15 1O% * Decanal 5 Orange terpenes mixture ¹⁾ q.s. Total1000 * in an orange terpenes mixture ¹⁾ origin: Firmenich SA, Geneva,Switzerland

Compounds 4, 13 and 17 were added to this base solution at a rate of 5ppm by weight each, to prepare three novel solutions which wereevaluated on a blind test, together with the base solution, by a panelof expert flavorists. In the opinion of the latter, the three novelsolutions all had a far juicier taste than the base solution.

EXAMPLE 39

Flavoring of Cola Light Type Beverages

To a base drink of the Cola “light” type, i.e. sugar lightened, ofcommercial origin, containing artificial sweeteners (35.6 mg of Sodiumcyclamate, 12.5 mg of Acesulfam® K and 12 mg of Aspartame®, per 100 mlof drink), there were added respectively 0.05 ppm of compound 5 (drinkA) and 0.05 ppm of compound 6 (drink B).

Drinks A and B, as well as the base drink, were then compared on a blindtest by a panel of expert flavorists. The latter indicated a particularpreference for drink B, which taste was judged stronger in the sugarnote, which lasted far longer in the mouth, relative to the basesolution. Similar effects were moreover observed by adding a proportionof 0.25 ppm by weight of compound 6.

As to drink A, it was also preferred to the base solution, its tastehaving more volume, being sweeter and more lemon-lime than that of thebase drink. The same was observed when compound 5 was added to thelatter in a proportion of 0.5 ppm.

EXAMPLE 40

Flavoring Composition

A flavoring composition according to the invention was prepared byadmixing in equivalent molar proportions 4-methyl-2-oxo-pentanoic acid(compound 6), 3-methyl-2-oxo-pentanoic acid (compound 5),2-oxo-3-phenylpropanoic acid (compound 11),4-(methylthio)-2-oxo-butanoic acid (compound 14) and2-oxo-1H-indole-3-propanoic acid (compound 13).

Upon adding this flavoring composition, at a rate of 3 ppm by weight, toa Cola “light” type drink such as cited in the previous example, a noveldrink was obtained, which possessed a sweeter and more pleasant tastethan the original drink, the characteristic aftertaste of the artificialsweeteners having been distinctly abated.

Other tests were also carried to evaluate the organoleptic effect of thesame flavoring composition upon cheese and butter type flavors. To thisend, there were added to a 0.5% of NaCl saline solution 150 ppm byweight of a cheese type flavor (504 132 TH; origin: Firmenich SA,Geneva, Switzerland). To this flavored base solution there was thenadded 1 ppm by weight of the flavoring composition cited above. Thenovel solution thus obtained, as well as the base solution, weresubsequently evaluated on a blind test by a panel of expert flavorists.The result of this evaluation showed a unanimous preference for thenovel solution and the flavorists indicated that the creamy character ofthe latter had been clearly enhanced relative to that of the basesolution, the rind type notes having also been somewhat toned down.

Upon similar tests with a butter type flavor (504 131 TH; origin:Firmenich SA, Geneva, Switzerland), added at a rate of 50 ppm by weight,it was also ascertained that the flavoring composition of the invention(1 ppm) improved the taste of said flavor, imparting to it an enhancedcreamy and buttery character.

EXAMPLE 41

Tea Type Flavoring Compositions

A tea tasting base flavor (502 911 T; 40 ppm by weight; origin:Firmenich SA, Geneva, Switzerland) was added to spring water to obtain aflavored base solution. When there were added to this base solution 2ppm by weight of compound 19, a novel solution was obtained having anenhanced straw like, dry leaves character.

On the other hand, compound 20, added in the same proportion, brings tothe base flavor a stronger black tea type note and reinforces thefullness of the composition and its slightly fruity herbaceous note.

EXAMPLE 42

Sugar Type Flavoring Compositions

To a base flavor of the type intended to mimic the taste of sugar (503407 B origin: Firmenich SA, Geneva, Switzerland) there was added aproportion of 0.8% by weight of compound 4 or its sodium salt. The novelcomposition thus obtained was then evaluated on a blind test by a panelof expert flavorists. According to the latter, the sugar taste of thenovel composition was far richer, with a distinctly enhanced molassesand caramel character relative to that of the base flavor.

This enriching effect on the sugar, molasses and caramel note couldlikewise be observed when the same compound 4 was added to a mixture ofFuraneol® (12% by weight), vanillin (5% by weight) and maltol (2% byweight).

What is claimed is:
 1. A method to improve, enhance or modify gustative impressions related to texture, volume or fullness, as perceived upon tasting, of a flavoring composition or a food product selected from the group consisting of light products having a low fat or sugar content, meat or meat-flavored products, bouillons, vegetable or vegetable-flavored products, fruit-juices, lemonades, and orange-flavored products, which method comprises adding to said composition or product a flavor and/or taste perceptible amount of one or more active ingredients selected from the group consisting of (a) the α-keto acids glyoxylic, 3-methyl-2-oxo-butanoic, 3-methyl-2-oxo-pentanoic, 4-methyl-2-oxo-pentanoic, 3-hydroxy-2-oxo-propanoic, oxalacetic, 2-oxo-glutaric, 2-oxo-3-phenyl-propanoic, 3-(4-hydroxyphenyl)-2-oxo-propanoic, 2-oxo-1H-indole-3-propanoic, 2-oxo-1H-imidazole-4-propanoic, 4-methylthio-2-oxo-butanoic, 3-mercapto-2-oxo-propanoic, 3-hydroxy-2-oxo-butanoic, 6-amino-2-oxo-hexanoic and 5-guanidino-2-oxo-pentanoic acid, and (b) the edible salts of the said α-keto acids, or a mixture of at least one of the compounds specified under (a) and (b) with the corresponding amino acid or acids.
 2. The method according to claim 1, characterized in that said active ingredient is formed of one or more of said α-keto acids or their edible salts, in combination with one or several amino acids selected from the group consisting of 2-amino-butanoic acid, α-alanine, glycine, norvaline, valine, aspartic acid, norleucine, leucine, isoleucine, serine, threonine, glutamic acid, phenylalanine, tyrosine, cysteine, methionine, lysine, tryptophane, histidine, arginine, asparagine, glutamine, cystine, citrulline, theanine, γ-methylene-glutamic acid and their alkaline metal salts.
 3. The method according to claim 2, characterized in that the amino acid or its salt is present in a weight proportion of between about 0.5 and 2 times that of the α-keto acid.
 4. The method according to claim 1, characterized in that said active ingredient is present in a proportion comprised between about 0.01 and 10% by weight, relative to the weight of the composition.
 5. The method according to claim 1, wherein said light product is a product containing an artificial sweetener.
 6. The method according to claim 1, wherein said light product is an instant dessert, a butter product, a margarine, a yoghurt, a milk product, a cola based drink, a tea, a lemonade or a fruit juice.
 7. The method according to claim 6, wherein said fruit-juice is an orange, blackcurrant or raspberry juice.
 8. The method according to claim 1, wherein the volume and fullness of fatty, roasted, chicken or beef flavor notes of a meat or a meat-flavored product is enhanced, improved or modified.
 9. The method according to claim 8, wherein the α-keto acid is selected from the group consisting of 2-oxo-butanoic, oxalacetic, 3-methyl-2-oxo-butanoic, 3-methyl-2-oxo-pentanoic, 2-oxo-glutaric and 3-mercapto-2-oxo-propanoic acid.
 10. The method according to claim 9, which further comprises adding one or several compounds selected from the group consisting of isoeugenol, 2-propylphenol, p-vinylguaiacol, 2-acetylpyrazine, 2-ethyl-3,5-dimethylpyrazine, 2,3,5-trimethylpyrazine, 2,3-diethyl-5-methylpyrazine, 3-ethyl-2-methylpyrazine, dimethyl sulfide, dimethyl disulfide, dimethyl trisulfide, methylpropyl disulfide, 2-methylthiophenol, methional (3-methylthiopropanal), 2-octenal, 2,4-nonadienal, 2,4-decadienal, 2,4-undecadienal, 2-methoxybenzaldchyde, 2,4-dodecadienal, decenal, methyl 2-furanecarboxylate, 2-ethyl-4-hydroxy-3-methyl 5(2H)-furanone, 2,6-dimethylbenzenethiol 2-nonen-1-ol, 10-undecenoic acid, undecanoic acid, isodecanoic acid and isononanoic acid.
 11. The method according to claim 1, wherein the volume and fullness of tomato, asparagus, corn or celery flavor notes of vegetable or vegetable-flavored products is enhanced, improved or modified. 